1. Field of the Invention
The present invention relates to an imaging device and an image processing method and, in particular, to an imaging device and an image processing method that perform moving image generation and focus adjustment based on phase difference in parallel.
2. Description of the Related Art
Conventionally, automatic focus adjustment (phase difference AF) has been known where first and second phase difference pixels on which a subject image having passed through left and right regions of an imaging lens is pupil-divided and image-formed are provided in a part of an image pickup element, the phase difference between output signals of the first and second phase difference pixels are detected, and the focus position of a focusing lens is adjusted on the basis of the detected phase difference.
An image pickup element described in PTL 1 (Japanese Patent Application Laid-Open No. 2009-89144) includes a typical Bayer array color filter. In the horizontal direction and the vertical direction, first pixels for detecting the focal position (pixels on the left side of pupil division) and second pixels for detecting the focal position (pixels on the right side of pupil division) are alternately arranged at a predetermined period (at a period of six pixels in the horizontal direction, and at a period of three pixels in the vertical direction). The first and second pixels for detecting the focal position are arranged on pixel positions where green (G) filters are arranged.
In the case of detecting the focal point, an electronic camera described in PTL 1 thinning-reads an image on lines (line image) where the first and second pixels for detecting the focal point are arranged, detects the focus position on the basis of the image signal of the first and second pixels for detecting the focal point in the thinning-read line image, and controls the position of the focusing lens, while performing live view display in real time on the basis of the image signal of the thinning-read line image (including the first and second pixels for detecting the focal point). In the case of not detecting the focal point, an line image where the first and second pixels for detecting the focal point are not arranged is read, and live view display is performed on the basis of the image signal of the line image.
In the case of detecting the focal point, the electronic camera described in PTL 1 pairs the first or second pixels for detecting the focal point (G pixels) and red pixels (R pixels) or blue pixels (B pixels) that are adjacent to the G pixels with each other and extracts signals from the thinning-read line image, and performs live view display on the basis of the image signal of the extracted pixels. Accordingly, image signals of typical G pixels (G pixels other than the first or second pixels for detecting the focal point) are not used for live view display in the case of detecting the focal point.
The layout of the color filter described in PTL 2 (Japanese Patent Application Laid-Open No. 2011-29379) is proposed as replacement for the Bayer-arrayed color filter.